Rewinders of this type are known, for example, from U.S. Pat. No. 4,487,377 and U.S. Pat. No. 5,137,225, or from the British Patent GB 2,105,688. Such rewinders are commonly used in the paper converting industry to produce, starting from parent rolls of large diameter, a plurality of rolls or logs of smaller diameter which are subsequently cut to form small rolls of toilet paper, all-purpose wipers, industrial rolls or the like.
Attempts have also been made to provide rewinders for producing rolls or logs without a core. For example, U.S. Pat. No. 4,487,378 shows a system for producing logs of wound web material in which the winding takes place on a mandrel which is subsequently withdrawn from the completed log. These winding systems are unsuitable to meet the current requirements of high productivity in this field.
One object of the present invention is to provide a surface automatic rewinding machine able to produce, at a high rate, rolls or logs of web material with or without winding core. A further object of the present invention is to provide a rewinding machine which is able to shift, in an extremely fast and simple way, and with no need for special adjustments, from the production of core logs to the production of coreless logs, and vice versa.